Lexus RX (RX 350L, RX450h) 2016-2024 Repair Manual: Transmission Fluid Temperature Sensor "A" Circuit Short To Ground (P071011)

Lexus RX (RX 350L, RX450h) 2016-2024 Repair Manual / Drivetrain / U881f (automatic Transmission / Transaxle) / Automatic Transaxle System / Transmission Fluid Temperature Sensor "A" Circuit Short To Ground (P071011)

DESCRIPTION

The ATF temperature sensor converts the automatic transaxle fluid (ATF) temperature into a resistance value for use by the ECM.

The ECM applies voltage to the temperature sensor through terminal THO1 of the ECM.

The sensor resistance changes with the ATF temperature. As the temperature rises, the sensor resistance decreases.

One terminal of the sensor is grounded so that the sensor resistance and voltage decrease as the temperature rises.

The ECM calculates the ATF temperature based on the voltage signal.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

Note

P071011

Transmission Fluid Temperature Sensor "A" Circuit Short To Ground

1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other

  • The battery voltage is 8 V or more, the engine switch is on (IG) and the starter is off.
  • ATF temperature sensor voltage is less than 0.142 V
  • 0.5 seconds
  • 1-trip detection logic
  • Short to ground in ATF temperature sensor circuit
  • Transmission wire (ATF temperature sensor)
  • ECM

Comes on

DTC stored

SAE Code:

P0712

MONITOR DESCRIPTION

This DTC indicates a short to ground in the ATF temperature sensor circuit. The ATF temperature sensor converts the ATF temperature into an electrical resistance value. Based on the resistance, the ECM determines the ATF temperature, and can detect a short to ground in the ATF temperature sensor circuit. If the resistance value of the ATF temperature sensor is below 79 Ω*, the ECM interprets this as a malfunction of the ATF temperature sensor or in the wire harness, illuminates the MIL and stores this DTC.

*: 150°C (302°F) or higher is indicated regardless of the actual ATF temperature.

HINT:

The ATF temperature can be checked in the Data List.

MONITOR STRATEGY

Related DTCs

P0712: ATF temperature sensor/Range check (Low voltage)

Required sensors/Components

ATF temperature sensor (TFT sensor)

Frequency of operation

Continuous

Duration

0.5 sec.

MIL operation

Immediate

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

The monitor will run whenever these DTCs are not present

None

Battery voltage

8 V or more

Engine switch

On (IG)

Starter

OFF

TYPICAL MALFUNCTION THRESHOLDS

TFT sensor voltage

(ATF temperature)

Less than 0.142 V

(More than 164°C (327°F))

COMPONENT OPERATING RANGE

ATF temperature sensor (TFT sensor) resistance

79 to 156 kΩ

CONFIRMATION DRIVING PATTERN

HINT:

  • After repairs have been completed, clear the DTCs and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
  • When clearing the permanent DTCs, refer to the Clear Permanent DTC procedure.

    Click here

  1. Connect the Techstream to the DLC3.
  2. Turn the engine switch on (IG) and turn the Techstream on.
  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  4. Turn the engine switch off and wait for 2 minutes or more.
  5. Turn the engine switch on (IG) and turn the Techstream on.
  6. Wait for 3 seconds or more with the engine switch on (IG). [*1]

    HINT:

    [*1] : Normal judgment procedure.

    The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.

  7. Enter the following menus: Powertrain / Transmission / Utility / All Readiness.
  8. Input the DTC: P071011.
  9. Check the DTC judgment result.

    Techstream Display

    Description

    NORMAL
    • DTC judgment completed
    • System normal

    ABNORMAL
    • DTC judgment completed
    • System abnormal

    INCOMPLETE
    • DTC judgment not completed
    • Perform driving pattern after confirming DTC enabling conditions

    N/A
    • Unable to perform DTC judgment
    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    HINT:

    • If the judgment result shows NORMAL, the system is normal.
    • If the judgment result shows ABNORMAL, the system has a malfunction.
    • If the judgment result shows INCOMPLETE or N/A, perform the normal judgment procedure again.

WIRING DIAGRAM

Refer to DTC P071000.

Click here

CAUTION / NOTICE / HINT

NOTICE:

  • Perform the universal trip to clear permanent DTCs.

    Click here

  • Perform registration and/or initialization when parts related to the automatic transaxle are replaced.

    Click here

DATA LIST

NOTICE:

In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not.

HINT:

Using the Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time.

(a) Warm up the engine.

(b) Turn the engine switch off.

(c) Connect the Techstream to the DLC3.

(d) Turn the engine switch on (IG).

(e) Turn the Techstream on.

(f) Enter the following menus: Powertrain / Transmission / Data List / A/T Oil Temperature No.1.

(g) Read the Data List according to the display on the Techstream.

Powertrain > Transmission > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

A/T Oil Temperature No.1

ATF temperature sensor value

Min.: -40°C (-40°F)

Max.: 150°C (302°F)
  • Approximately 80°C (176°F): After stall speed test
  • Equal to ambient temperature: When engine is cold

If value is -40°C (-40°F) or 150°C (302°F), ATF temperature sensor circuit is open or shorted
Powertrain > Transmission > Data List

Tester Display

A/T Oil Temperature No.1

HINT:

  • If DTC P071011 is output and the Techstream indicates 150°C (302°F) or higher, there is a short in the circuit.
  • If DTC P071015 is output and the Techstream indicates -40°C (-40°F), the circuit is open.

    Check the temperature displayed on the Techstream in order to check if a malfunction exists.

    Temperature Displayed

    Malfunction

    -40°C (-40°F)

    Open circuit

    150°C (302°F) or higher

    Short circuit

PROCEDURE

1.

READ VALUE USING TECHSTREAM

(a) Warm up the engine.

(b) Turn the engine switch off.

(c) Connect the Techstream to the DLC3.

(d) Turn the engine switch on (IG).

(e) Turn the Techstream on.

(f) Enter the following menus: Powertrain / Transmission / Data List / A/T Oil Temperature No.1.

(g) Read the Data List according to the display on the Techstream.

Powertrain > Transmission > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

A/T Oil Temperature No.1

ATF temperature sensor value

Min.: -40°C (-40°F)

Max.: 150°C (302°F)
  • Approximately 80°C (176°F): After stall speed test
  • Equal to ambient temperature: When engine is cold

If value is -40°C (-40°F) or 150°C (302°F), ATF temperature sensor circuit is open or shorted
Powertrain > Transmission > Data List

Tester Display

A/T Oil Temperature No.1

Result

Proceed to

Data List value is normal

A

Data List value is not normal

B
A

GO TO STEP 3

B

2.

CHECK HARNESS AND CONNECTOR (ATF TEMPERATURE SENSOR - ECM)

(a) Disconnect the D2 ECM connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

D2-86 (THO1) - D2-133 (ETHW)

Always

79 Ω to 156 kΩ

D2-133 (ETHW) - Body ground

Always

10 kΩ or higher

D2-86 (THO1) - Body ground

Always

10 kΩ or higher

HINT:

If the resistance is out of the specified range at any of the ATF temperatures shown in the table below, the driveability of the vehicle may decrease.

ATF Temperature

Specified Condition

10°C (50°F)

5 to 8 kΩ

25°C (77°F)

2.5 to 4.5 kΩ

110°C (230°F)

0.22 to 0.28 kΩ
NG

GO TO STEP 4

OK

3.

REPLACE ECM

(a) Replace the ECM.

Click here

NEXT

PERFORM A/T CODE REGISTRATION

4.

CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)

(a) Disconnect the D56 transmission wire connector.

(b) Disconnect the D2 ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

D56-8 (OIL) or D2-86 (THO1) - Body ground

Always

10 kΩ or higher

D56-9 (E2) or D2-133 (ETHW) - Body ground

Always

10 kΩ or higher
OK

REPLACE TRANSMISSION WIRE (ATF TEMPERATURE SENSOR)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (TRANSMISSION WIRE - ECM)
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